nbstripout

#!/usr/bin/env python
"""strip outputs from an IPython Notebook

Opens a notebook, strips its output, and writes the outputless version to the original file.

Useful mainly as a git pre-commit hook for users who don't want to track output in VCS.

This does mostly the same thing as the `Clear All Output` command in the notebook UI.
"""

import io
import sys

from IPython.nbformat import current

def strip_output(nb):
    """strip the outputs from a notebook object"""
    nb.metadata.pop('signature', None)
    for cell in nb.worksheets[0].cells:
        if 'outputs' in cell:
            cell['outputs'] = []
        if 'prompt_number' in cell:
            cell['prompt_number'] = None
    return nb

if __name__ == '__main__':
    filename = sys.argv[1]
    with io.open(filename, 'r', encoding='utf8') as f:
        nb = current.read(f, 'json')
    nb = strip_output(nb)
    with io.open(filename, 'w', encoding='utf8') as f:
        current.write(nb, f, 'json')

pre-commit

#!/bin/sh
#
# strip output of IPython Notebooks
# add this as `.git/hooks/pre-commit`
# to run every time you commit a notebook
#
# requires `nbstripout` to be available on your PATH
#

if git rev-parse --verify HEAD >/dev/null 2>&1; then
   against=HEAD
else
   # Initial commit: diff against an empty tree object
   against=4b825dc642cb6eb9a060e54bf8d69288fbee4904
fi
 
# Find notebooks to be committed
(
IFS='
'
NBS=`git diff-index -z --cached $against --name-only | grep '.ipynb$' | uniq`

for NB in $NBS ; do
    echo "Removing outputs from $NB"
    nbstripout "$NB"
    git add "$NB"
done
)

exec git diff-index --check --cached $against --